1. Technical Field
Aspects of the present invention relate to a management apparatus, which manages digital certificates written with the period of validity.
2. Related Art
Heretofore, as for communication technology, SSL (Secure Socket Layer) communication technique is widely used. In SSL communication, a public key is notified through a digital certificate (digital ID) to enter into a cipher communication. In order to establish high-security communication, a digital certificate used in SSL communication is commonly set its effective period, and an expired digital certificate is generally prohibited to use for the communication.
Therefore, each owner of the digital certificate is required to grasp the expiration date in possession always, and required to carry out updating operation of the digital certificate as appropriate. However, some owners may forget the expiration date, and in case of losing the period, the users may be unable to use the terminal unit in network using the digital certificate when necessary. That is to say, a communication system using the digital certificate has been inconvenient on this point for users.
Japanese Patent Provisional Publication No. 2005-269558 (hereafter, referred to as JP 2005-269558A) discloses a technique for resolving the problem of validity expiration. According to the technique disclosed in JP 2005-269558A, the approaching expiration date is notified to users by e-mail in accordance with each expiration date of the digital certificate.
Conventionally, however, it was a sort of sending an e-mail written with a message for urging update of the digital certificate simply according to the expiration date and that may press users annoying to move on to updating operation. As a consequence of such mood of the users, carrying out updating operation may be delayed, and some users may cause expiration of the digital certificate in spite of having been warned.